Fluorescence study, hydrophobically modified poly

Interactions of Hydrophobically Modified Poly(A -Isopropylacrylamides) with Liposomes Fluorescence Studies... 

Ringsdorf H, Venzmer J, Winnik FM (1991) Fluorescence studies of hydrophobically modified poly(Af-isopropylacrylamide) or how to play accordion on a liposome. Makromol Chem Macromol Symp 46 427-431... 

Hu Y-Z, Zhao C-L, Winnik MA, Sundararajan PR (1990) Fluorescence studies of the interaction of sodium dodecyl sulfate with hydrophobically modified poly(ethylene oxide). Langmuir 6 880-883... 

The surfaces of liposomes have been coated [17] with thermosensitive pol5uners such as poly(A -isopropylacrylamide) [poly(NIPAM)] by taking advantage of the phase transition of polymers. The molecular structure of a hydrophobically modified poly(NIPAM), which has been studied in the preparation of temperature-sensitive Uposomes [17], is depicted in Fig. 7. Poly(NlPAM) exhibits a low critical solution temperature (LCST) around 32°C, and the LCST can be altered toward the body temperature by co-pol5unerization [56], The pol5uner is in an expanded form at low temperature, but above the critical temperature it is in a contracted form. The interactions of SUVs and hydrophobically modified poly(NIPAM) were studied by fluorescence spectroscopy [88]. More recently, sonicated DPPC and egg PC Uposomes coated with a copolymer of NIPAM and octadecylacrylate in a molar ratio of 100 1 were prepared [17,89], It was shown that above the LCST of the copolymer, the release of calcein and carboxyfluorescein from... 

Photophysical studies on a conformational transition of PMA induced by cationic surfactants have been reported (7). The stretched PMA chain at pH 8 collapses on addition of cationic surfactants that is, the hydrophobic interactions between the cationic surfactants that are bonded to the PMA chain lead to refolding of the polymer chain, and thus provide a hydrophobic site for fluorescence probes at pH 8. The cationic polyelectrolyte poly(4-vinylpyridine) quatemized with n-dodecyl bromide (8 i0) or hexadecyl bromide (11) are also examples of hydrophobically modified polyelectrolytes. 

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